In water wells, oil wells and gas wells, a subterranean well bore extends beneath the ground to a supply of water, oil or gas which is extracted to the ground surface, typically to supply a home or business. A well casing typically lines the well bore. The water, oil or gas is pumped from the subterranean source to the ground surface through a tubing string which extends downwardly through the well bore. The tubing string typically includes multiple subunits which are connected to each other by couplings in the assembled tubing string.
In positioning the tubing string in the well bore, it is frequently desirable to maintain the tubing string in the center of the bore, or at least spaced from the well casing or interior well surface, to facilitate unhindered passage of packing material, for example, into the well, between the casing or interior surface of the well and the tubing string. For this purpose, centralizers having outwardly-extending projections are frequently placed on the tubing string to contact the well casing or interior surface of the well and maintain the tubing string typically in the approximate center of the well bore. However, many centralizers of conventional design are difficult to assemble on the tubing string in the field. Thus, a centralizer is need which is versatile and is easy to assemble in place on a tubing string.